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Critical Care and Resuscitation :... Sep 2020Albumin is the most abundant and perhaps most important protein in human blood. Research has identified many of albumin's possible roles in modulating acid-base balance,... (Review)
Review
Albumin is the most abundant and perhaps most important protein in human blood. Research has identified many of albumin's possible roles in modulating acid-base balance, modifying inflammation, maintaining vascular endothelial integrity, and binding endogenous and exogenous compounds. Albumin plays a key role in the homeostasis of vascular endothelium, offering protection from inflammation and damage to the glycocalyx. Albumin binds a diverse range of compounds. It transports, delivers and clears drugs, plus it helps with uptake, storage and disposal of potentially harmful biological products. The biological effects of albumin in critical illness are incompletely understood, but may enhance its clinical role beyond use as an intravenous fluid. In this article, we summarise the evidence surrounding albumin's biological and physiological effects beyond its use for plasma volume expansion, and explore potential mechanistic effects of albumin as a disease modifier in patients with critical illness.
Topics: Albumins; Endothelial Cells; Endothelium, Vascular; Glycocalyx; Homeostasis; Humans
PubMed: 32900333
DOI: 10.1016/S1441-2772(23)00394-0 -
PloS One 2021Complications following total knee arthroplasty (TKA) lead to patient morbidity and cost. While acute phase reactants, such as c-reactive protein (CRP) and fibrinogen,...
PURPOSE
Complications following total knee arthroplasty (TKA) lead to patient morbidity and cost. While acute phase reactants, such as c-reactive protein (CRP) and fibrinogen, have been used to predict complications following TKA, the extent and duration of changes in albumin levels following TKA are unknown. It is hypothesized that like CRP and fibrinogen, albumin, and the fibrinogen/albumin ratio (FAR) represent useful measures of the acute phase response (APR) following TKA. The purpose of this study was to describe the longitudinal course of albumin and FAR in healthy patients following TKA, relative to established biomarkers, and examine if the variance in albumin or FAR correlates with patient comorbidities.
METHODS
This retrospective cohort study of patients undergoing TKA at a tertiary medical center. CRP, fibrinogen, and albumin values were collected pre- and post-operatively. An age-adjusted Charlson comorbidity index (CCI) was utilized as a measure of patient comorbidity status.
RESULTS
The median preoperative albumin value was 4.3 g/dL, which dropped to 3.6 g/dL on postoperative day 1 following TKA. The albumin value returned to 93% of the baseline by postoperative week 2. The course of albumin inversely mirrored the course of CRP (r = -0.41). Median preoperative FAR was 0.087 g/L, which rose to 0.130 g/L by postoperative week 2 and returned to baseline by postoperative week 6. While preoperative FAR strongly correlated with postoperative week 2 values (r = 0.74), there was a weak positive correlation between age-adjusted CCI and pre-operative FAR (r = 0.24) in patients undergoing primary TKA.
CONCLUSION
Albumin levels follow a predictable postoperative decline that inversely correlates with CRP in healthy patients following TKA. Given the low cost and abundance of laboratories offering albumin levels, direct albumin levels and/or albumin ratios such as FAR may be underutilized biomarkers for monitoring the APR following TKA.
Topics: Acute-Phase Reaction; Adult; Aged; Aged, 80 and over; Albumins; Arthroplasty, Replacement, Knee; Biomarkers; Female; Fibrinogen; Humans; Male; Middle Aged; Postoperative Care; Retrospective Studies; STAT3 Transcription Factor
PubMed: 33592030
DOI: 10.1371/journal.pone.0247070 -
Acta Gastro-enterologica Belgica 2019Low serum albumin is common in cirrhosis and is associated with a reduced survival. Moreover, in this setting, the native isoform of albumin can be severely reduced due... (Review)
Review
Low serum albumin is common in cirrhosis and is associated with a reduced survival. Moreover, in this setting, the native isoform of albumin can be severely reduced due to several posttranscriptional changes that impair the non-oncotic properties of the molecule. Due to its oncotic power, albumin acts as a powerful plasma expander. As such, it can antagonize the consequences of effective hypovolemia deriving from the systemic hemodynamics abnormalities that characterize advanced cirrhosis. Indeed, the current established indications to the use of albumin in this context pertain to conditions deriving from an acute drop of effective volemia. Recent advances have shown that the pathophysiological background of decompensated cirrhosis is characterized by a sustained systemic inflammatory and pro-oxidant state deriving by an abnormal bacterial translocation from the gut. These abnormalities ultimately lead to the multiorgan dysfunction. In this cascade of events, long-term albumin administration could act against several pathogenic factors through its non-oncotic properties, thus representing a potential multi-target mechanistic treatment. Over the last year, two randomized clinical trials on this topic were published. The ANSWER Trial demonstrated that the long-term albumin administration in patients with decompensated cirrhosis improves overall survival, reduces the incidence of complications and the need of hospitalizations and ameliorates the quality of life, being cost-effective. The MACHT trial challenged these results, but the differences between the two studies (sample size, baseline severity of cirrhosis, length of follow-up and amount of albumin administered) could explain its variant results, providing the basis for further insights into this matter.
Topics: Albumins; Fibrosis; Humans; Hypovolemia; Liver Cirrhosis; Quality of Life; Serum Albumin
PubMed: 31314192
DOI: No ID Found -
Theranostics 2017Biosafety is the primary concern in clinical translation of nanomedicine. As an intrinsic ingredient of human blood without immunogenicity and encouraged by its... (Review)
Review
Biosafety is the primary concern in clinical translation of nanomedicine. As an intrinsic ingredient of human blood without immunogenicity and encouraged by its successful clinical application in Abraxane, albumin has been regarded as a promising material to produce nanoparticles for bioimaging and drug delivery. The strategies for synthesizing albumin-based nanoparticles could be generally categorized into five classes: template, nanocarrier, scaffold, stabilizer and albumin-polymer conjugate. This review introduces approaches utilizing albumin in the preparation of nanoparticles and thereby provides scientists with knowledge of goal-driven design on albumin-based nanomedicine.
Topics: Albumins; Drug Delivery Systems; Humans; Nanomedicine; Nanoparticles
PubMed: 29109768
DOI: 10.7150/thno.19365 -
Molecular Medicine Reports Feb 2024Human serum albumins (HSAs) are synthesized in the liver and are the most abundant proteins in plasma of healthy human. They play an important role in the... (Review)
Review
Human serum albumins (HSAs) are synthesized in the liver and are the most abundant proteins in plasma of healthy human. They play an important role in the pathophysiological processes of the liver and even the whole organism. Previous studies have mainly focused on the regulation of HSAs' expression. However, with the progress of research in recent years, it has been found that the content of circulating albumin cannot fully reflect the biological function of albumin itself. Given the aforementioned fact, the concept of serum 'effective albumin concentration' has been proposed. It refers to the content of albumin that is structurally and functionally intact. Alterations in the molecular structure and function of albumin have been reported in a variety of diseases, including liver disease. Moreover, these changes have been verified to affect the progression of oxidative stress‑related diseases. However, the link between albumin structure and function has not been fully elaborated, and the mechanisms by which different forms of albumin affect disease also need to be further investigated. In this context, the present review mainly expounded the biological characteristics and functions of albumin, summarized the different types of post‑translational modification of albumin, and discussed their functional changes and possible mechanisms in non‑alcoholic fatty liver disease, alcoholic hepatitis, viral hepatitis and different stages of cirrhosis. This will help to improve understanding of the role of albumin in disease development and provide a more comprehensive physiological basis for it in disease treatment.
Topics: Humans; Albumins; Liver Cirrhosis; Serum Albumin; Serum Albumin, Human; Non-alcoholic Fatty Liver Disease
PubMed: 38099350
DOI: 10.3892/mmr.2023.13147 -
Molecules (Basel, Switzerland) Dec 2022Albumin nanocolloids have been used as radiopharmaceuticals for more than 40 years. Their main use is in lymphoscintigraphy and the detection of the sentinel lymph node... (Review)
Review
Albumin nanocolloids have been used as radiopharmaceuticals for more than 40 years. Their main use is in lymphoscintigraphy and the detection of the sentinel lymph node as part of the surgical treatment of a variety of solid tumours. The main licensed products are labelled with the gamma emitter technetium-99m. Recently, two analogues labelled with positron emitters have been reported, using gallium-68 and zirconium-89. For about 10 years, there has been interest in dual-modal agents with both radioactive and fluorescent labels to improve the localisation of the sentinel lymph node. Indocyanine green (ICG) has been the most widely used fluorescent label, largely due to its availability as a licensed agent and its ease of application. The further development of alternative radiolabels or improved fluorescent tags will require investment in the development and licensing. There is also a vast potential for the targeting of albumin nanocolloids using existing strategies, which could be promising for the development of both diagnostic and therapeutic agents.
Topics: Radiopharmaceuticals; Technetium Tc 99m Aggregated Albumin; Sentinel Lymph Node Biopsy; Lymphoscintigraphy; Coloring Agents; Albumins; Lymph Nodes
PubMed: 36500689
DOI: 10.3390/molecules27238596 -
PloS One 2022Glycation process refers to reactions between reduction sugars and amino acids that can lead to formation of advanced glycation end products (AGEs) which are related to...
Glycation process refers to reactions between reduction sugars and amino acids that can lead to formation of advanced glycation end products (AGEs) which are related to changes in chemical and functional properties of biological structures that accumulate during aging and diseases. The aim of this study was to perform and analyze in vitro glycation by fructose and methylglyoxal (MGO) using salivary fluid, albumin, lysozyme, and salivary α-amylase (sAA). Glycation effect was analyzed by biochemical and spectroscopic methods. The results were obtained by fluorescence analysis, infrared spectroscopy (total attenuated reflection-Fourier transform, ATR-FTIR) followed by multivariate analysis of principal components (PCA), protein profile, immunodetection, enzymatic activity and oxidative damage to proteins. Fluorescence increased in all glycated samples, except in saliva with fructose. The ATR-FTIR spectra and PCA analysis showed structural changes related to the vibrational mode of glycation of albumin, lysozyme, and salivary proteins. Glycation increased the relative molecular mass (Mr) in protein profile of albumin and lysozyme. Saliva showed a decrease in band intensity when glycated. The analysis of sAA immunoblotting indicated a relative reduction in intensity of its correspondent Mr after sAA glycation; and a decrease in its enzymatic activity was observed. Carbonylation levels increased in all glycated samples, except for saliva with fructose. Thiol content decreased only for glycated lysozyme and saliva with MGO. Therefore, glycation of salivary fluid and sAA may have the potential to identify products derived by glycation process. This opens perspectives for further studies on the use of saliva, an easy and non-invasive collection fluid, to monitor glycated proteins in the aging process and evolution of diseases.
Topics: Adult; Albumins; Female; Fructose; Glycation End Products, Advanced; Glycosylation; Healthy Volunteers; Humans; Male; Muramidase; Oxidative Stress; Pyruvaldehyde; Saliva; Salivary Proteins and Peptides; Spectrometry, Fluorescence
PubMed: 35061788
DOI: 10.1371/journal.pone.0262369 -
Cells Dec 2022The neonatal Fc receptor (FcRn) is highly expressed in the renal proximal tubule and is important for the reclamation of albumin by cellular transcytosis to prevent its...
The neonatal Fc receptor (FcRn) is highly expressed in the renal proximal tubule and is important for the reclamation of albumin by cellular transcytosis to prevent its loss in the urine. The initial event of this transcellular transport mechanism is the endocytosis of albumin by the apical scavenger receptors megalin and cubilin. An interaction of megalin and FcRn was postulated, however, evidence is still missing. Similarly, the intracellular trafficking of FcRn remains unknown and shall be identified in our study. Using a Venus-based bimolecular fluorescence complementation system, we detected an interaction between megalin and FcRn in the endosomal compartment, which significantly increased with the induction of endocytosis using albumin or lactoglobulin as a ligand. The interaction between megalin and FcRn occurred at a neutral and acidic pH between the extracellular domains of both proteins. Amnionless, another transmembrane acceptor of cubilin, revealed no interaction with FcRn. With the induction of endocytosis by albumin or lactoglobulin, super resolution microscopy demonstrated a redistribution of megalin and FcRn into clathrin vesicles and early endosomes. This trafficking into clathrin vesicles was impaired in megalin-deficient cells upon albumin-induced endocytosis, supporting the role of megalin in FcRn redistribution. Our results indicate that megalin and FcRn specifically bind and interact within their extracellular domains. The availability of megalin is necessary for the redistribution of FcRn. Megalin, therefore, orchestrates FcRn endocytosis and intracellular trafficking as an early event intranscytosis.
Topics: Albumins; Clathrin; Endocytosis; Ligands; Low Density Lipoprotein Receptor-Related Protein-2; Protein Transport
PubMed: 36611847
DOI: 10.3390/cells12010053 -
Annals of Hepatology 2023
Topics: Humans; Liver Cirrhosis; Albumins; Treatment Outcome; Infusions, Intravenous
PubMed: 37659473
DOI: 10.1016/j.aohep.2023.101150 -
BMC Surgery Apr 2022A meta-analysis of randomized controlled trials was recently published in BMC Surgery that compared the use of human albumin with 6% hydroxyethyl starches 130/0.4 for... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
A meta-analysis of randomized controlled trials was recently published in BMC Surgery that compared the use of human albumin with 6% hydroxyethyl starches 130/0.4 for cardiopulmonary bypass prime and perioperative fluid management in pediatric and adult cardiac surgery patients. The two plasma expanding solutions are described as equivalent for efficacy and safety outcomes, and, on that basis, the preferential use of hydroxyethyl starches 130/0.4 was recommended for economic reasons because of the higher unit costs of human albumin solutions.
RESULTS
In addition to the fact that trials were mostly small, single-center studies and the number of total participants was low, making the meta-analysis underpowered for several outcomes, selective reporting of data for ICU length of stay was identified. Re-calculation of statistics at higher precision showed that ICU length of stay of patients in the human albumin group was significantly shorter than that of patients in the 6% hydroxyethyl starches 130/0.4 group (standard mean difference - 0.181, 95% confidence interval - 0.361 to - 0.001, P = 0.049), which may offset any proposed economic advantage of using 6% hydroxyethyl starches 130/0.4. At the same time, the renal safety of 6% hydroxyethyl starches 130/0.4 in surgical patients is under regulatory review.
CONCLUSIONS
Underpowered trials and selective reporting may impair the validity of the meta-analysis. A more cautious conclusion about the interchangeability between human albumin and 6% hydroxyethyl starches 130/0.4 in cardiac surgery should have been reached.
Topics: Adult; Albumins; Cardiac Surgical Procedures; Child; Humans; Hydroxyethyl Starch Derivatives; Plasma Substitutes; Serum Albumin, Human
PubMed: 35410195
DOI: 10.1186/s12893-022-01588-x